Biomedical subjects

Gastón Chamorro

Publications and source records attributed to Gastón Chamorro.

9 recordsLinked to original sources

PubMed2005

[Long-term results of repair versus replacement for degenerative mitral valve regurgitation].

BACKGROUND: Mitral valve repair is considered better than mitral valve replacement for degenerative mitral regurgitation. AIM: To evaluate late clinical results of mitral valve repair as compared to mitral valve replacement in patients with degenerative mitral regurgitation. PATIENTS AND METHODS: All patients subjected to open heart surgery for degenerative mitral regurgitation between 1990 and 2002 were assessed for surgical mortality, late cardiac and overall mortality, reoperation, readmission to hospital, functional capacity and anticoagulant therapy. Eighty eight patients (48 males) had mitral valve repair and 28 (19 males) had mitral valve replacement (23 with a mechanical prosthesis). Mean age was 59.9 +/- 14.8 (SD) and 61.3 +/- 14.6 years, respectively. Sixty three percent of patients with repair and 50% of those with valve replacement were in functional class III or IV before surgery. RESULTS: Operative mortality was 2.3% for mitral valve repair and 3.6% for mitral valve replacement (NS). Also, there was no statistical difference in the need of reoperation during the follow-up period between both procedures (2.3% and 0%, respectively). Ninety four percent of the replacement patients but only 26% of the repair patients were in anticoagulant therapy at the end of the follow-up period (p < 0.001). Ten years survival rates were 82 +/- 6% for mitral valve repair and 54 +/- 11% for replacement. The corresponding cardiac related survival rates were 89 +/- 6% and 79 +/- 10%. At the end of follow-up, all surviving patients were in functional class I or II. Ten years freedom from cardiac event rates (death, cardiac related rehospitalization and reoperation) were 90 +/- 3% for mitral valve repair and 84 +/- 6% for replacement. CONCLUSION: Repair of the mitral valve offers a better overall survival and a better chance of freedom from cardiac events as well as need for anticoagulation 10 years after surgery.

Adolescent↗

PubMed2005

[Prevalence of cardiovascular risk factors among patients suffering vascular events on admission and one year later].

BACKGROUND: International studies show a low compliance with norms for the management of cardiovascular risk factors. AIM: To assess the prevalence of risk factors in patients admitted for a coronary or vascular event and to evaluate the proportion of patients that normalize these factors after one year of follow up. MATERIAL AND METHODS: Three hundred and fifty seven patients aged 64+/-13 years (264 males), admitted to a University Clinical Hospital for a coronary or vascular event were studied. They were educated about cardiovascular risk factors and followed by their treating physicians for a mean of 11.9+/-2 months. During this period, smoking habits, body mass index. blood pressure, serum lipid levels, blood glucose and the appearance of new cardiovascular events were registered. RESULTS: One year survival was 96% (all 13 deaths were of cardiac origin). Eighty seven percent of patients were free of major cardiovascular events. At discharge from hospital and at the end of follow up 49% and 44% had a total cholesterol over 200 mg/dl respectively, 9,6% and 20,8% had systolic pressure over 140 mmHg. There was no diastolic hypertension in these patients, 27% and 31% had a body mass index over 25 kg/m2 and 2% smoked (versus 32% before the event). CONCLUSIONS: After one year of follow up, the prevalence of risk factors in patients that had suffered a cardiovascular event, continues to be high.

Cardiovascular Diseases↗

PubMed2005

[Valve repair surgery for incompetent bicuspid aortic valves].

BACKGROUND: Surgical valve repair is a good alternative for correction of incompetent bicuspid aortic valve. AIM: To report the early and late surgical, clinical and ecochardiographic results of surgical repair of incompetent bicuspid aortic valves. PATIENTS AND METHODS: Retrospective review of medical records of 18 patients aged 19 to 61 years, with incompetent bicuspid aortic valve in whom a valve repair was performed. Four patients had infectious endocarditis and 17 were in functional class I or II. Follow up ranged from 3 to 113 months after surgery. RESULTS: A triangular resection of the prolapsing larger cusp, which included the middle raphe, was performed in 17 cases; in 13 of these, a complementary subcommisural annuloplasty was performed. In the remaining case, with a perforation of the non-coronary cusp, a pericardial patch was implanted; this procedure was also performed in 2 other cases. In 3 cases large vegetations were removed. Postoperative transesophageal echocardiography showed no regurgitation in 11 patients (62%) and mild regurgitation in 7 (38%). There was no operative morbidity or mortality. There were no deaths during the follow-up period. In 3 patients (17%) the aortic valve was replaced with a mechanical prosthesis, 8 to 108 months after the first operation. Reoperation was not needed in 93%+/-6,4% at 1 year and 85%+/-9,5% at 5 years, these patients were all in functional class I at the end of the follow-up period. 60% had no aortic regurgitation, 20% had mild and 20% moderate aortic regurgitation on echocardiographic examination. A significant reduction of the diastolic diameter of the left ventricle was observed, but there were no significant changes in systolic diameter or shortening fraction. CONCLUSIONS: Surgical repair of incompetent bicuspid aortic valves has low operative morbidity and mortality and has a low risk of reoperation.

Adult↗

PubMed2004

[Valve repair surgery in infectious endocarditis].

BACKGROUND: Valve replacement has been the treatment of choice for patients with valvular complications of infectious endocarditis (IE). However, excellent results with valve repair allowed it to become a new therapeutic alternative for these patients. AIM: To evaluate the results of valve repair in patients with valvular complications of IE. PATIENTS AND METHODS: From January 1991 to December 2000, 14 patients with valvular complications of IE underwent valve repair. Mean age was 37.9 +/- 14.9. RESULTS: New York Heart Association (NYHA) class was 2.8 +/- 0.9. IE was located in the aortic in 6 (42%), in the mitral valve in 4 (29%) and in both valves in 4 cases (29%). Surgical indication was hemodynamic in 50% of the cases, echocardiographic in 29% and septic in 21%. Five aortic valves were bicuspid, 3 mitral valves were myxomatous and the rest were normal. The most common septic lesions were vegetations and leaflet perforations. A total of 23 aortic and 21 mitral valve repair procedures were performed. There were no deaths. Only 1 patient had a surgical complication (renal failure and prolonged mechanical ventilation). Follow-up was 100% complete. There was not late mortality. One patient with bone marrow aplasia required reoperation for a new episode of IE 19 months later. At the end of the follow-up NYHA class was 1.3 +/- 0.6 and echocardiography showed a mild or absence of valve regurgitation in most patients. CONCLUSIONS: Valve repair surgery in IE has good results, with advantages over valve replacement.

Adolescent↗

PubMed2003

Administration of growth hormone to patients with advanced cardiac heart failure: effects upon left ventricular function, exercise capacity, and neurohormonal status.

Experimental and clinical studies have shown that the administration of recombinant human growth hormone can improve deteriorated left ventricular function and hemodynamics in patients with heart failure. Herein, we compared the effects of growth hormone versus placebo upon resting left ventricular ejection fraction, exercise capacity and neurohormonal status in patients with advanced heart failure. Nineteen patients with advanced cardiac heart failure (ejection fraction <30%) were studied at baseline and after 8 weeks of treatment with growth hormone (0.03 U/kg per day) or placebo. Primary end points were resting left ventricular ejection fraction, peak oxygen consumption and neurohormonal status, including plasma norepinephrine levels and insulin like growth factor-1 and its binding protein-3. Results are presented as median and interquartile ranges. Patients receiving growth hormone had a significant increase in insulin growth factor-1 plasma levels (median difference growth hormone=83 ng/ml [57-170] versus placebo=-6 ng/ml [-23-6], P<0.05) and its binding protein-3. However, no significant increase in left ventricular ejection fraction after growth hormone treatment (ejection fraction pre=16% [13-18] and post=17% [14-27]) was noticed when compared to placebo (ejection fraction pre=20% [15-24] and post=20% [15-26]). Also, no significant effect of growth hormone treatment was seen on peak oxygen consumption or norepinephrine plasma levels. Although the administration of growth hormone to patients with advanced cardiac heart failure was associated with a significant increase in insulin growth factor-1, there were no significant changes in ejection fraction, exercise capacity and/or neurohormonal status.

Aged↗

PubMed2003

[Long-term results of repair surgery of degenerative mitral insufficiency].

BACKGROUND: Mitral valve repair is probably the procedure of choice for the surgical treatment of degenerative mitral insufficiency. AIM: To evaluate the late results of mitral valve repair in degenerative mitral insufficiency. PATIENTS AND METHOD: The records of 88 patients who underwent mitral valve repair for degenerative mitral insufficiency from December 1991 through June 2002 were reviewed. Mean age was 59.9 years (range 22 to 82). At least moderate mitral insufficiency was present in every patient. Mean left atrial diameter was 55 mm and mean end diastolic and end systolic left ventricular diameters were 61 and 37 mm respectively. RESULTS: The most common underlying lesion was ruptured chordae tendineae (66%) and posterior leaflet prolapse (68%). The surgical procedure most frequently performed was quadrilateral resection of the posterior leaflet (68%). A Carpentier-Edwards ring was placed in 97% of patients. An associated procedure was performed in 34%. Operative mortality was 2.3%. A complete follow up was obtained in 93% of cases with a mean of 54 +/- 36 months. Overall survival rate was 98% at one year, 88% at 5 and 82% at 10 years. Free of cardiac death rates were 94% at 5 and 89% at 10 years. Only 2 patients were reoperated during follow up, resulting in a 98% reoperation free rate follow up. Functional class improved in all patients at the end of follow up. Late echocardiographic evaluation showed absent or minimal mitral regurgitation in 83% and mild mitral regurgitation in 17%. CONCLUSION: Good late results have been obtained with mitral valve repair, avoiding the inconveniences of prosthetic replacement. Therefore, mitral valve repair should be the procedure of choice to treat degenerative mitral insufficiency.

Adult↗

PubMed2002

[Surgery for mitral valve insufficiency].

BACKGROUND: Ischemic mitral regurgitation (IMR) is a severe condition which may be best treated by surgery, notwithstanding a relatively high mortality rate. OBJECTIVES: To evaluate the results of mitral valve replacement or repair in patients with IMR. PATIENTS AND METHODS: Retrospective review of the clinical records in 29 patients with IMR who were surgically treated from 1990 to 1999. They represent 8% of surgical procedures on the mitral valve. RESULTS: Mean age was 67 +/- 9 years. Surgery was performed urgently in 19 patients (66.5%). NYHA functional class was 3.4 +/- 0.8. The mechanism of IMR was annular dilatation and spreading of papillary muscles in 18 patients, papillary muscle rupture in 9 and fibrosis in 2. Mitral valve replacement was performed in 14 patients and mitral valve repair in 15. Twenty four patients (83%) had concomitant myocardial revascularization. Overall surgical mortality was 24%; 26% for mitral replacement and 13% for mitral valve repair (p = 0.215). On follow up of 26 +/- 33 months, one year survival was 76 +/- 0.8% and 5 years survival was 59 +/- 12%. Excluding in hospital mortality, survival was 100% at one year and 78 +/- 14% at 5 years. Functional class improved in all survivors, to 1.4 +/- 0.5. Late echocardiographic evaluation of patients with mitral valve repair showed absence of mitral regurgitation in 58%, 1+ MR in 17% and 2+ MR in 25%. CONCLUSION: In spite of a high perioperative mortality, surgery for IMR is a valuable procedure for patients with an otherwise highly lethal disease.

Aged↗

PubMed2002

[A 36 years experience with implantable pacemakers. A historical analysis].

BACKGROUND: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. AIM: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. MATERIAL AND METHODS: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificación de Chile (Chilean Civil and Identification Registry). RESULTS: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74% from 1988 to 1998. Complication rate was 42% in the 1963-1976 study period, it decreased to 10.6% in the 1977-1987 study period, and to 5.6% by 1988-1998. Only two patients died during surgery in the study period (0.08%). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52% at ten years, 33% at 15 years, and 21% at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. CONCLUSIONS: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures.

Aged↗

PubMed2002

Angiotensin I-converting enzyme insertion/deletion polymorphism and adrenergic response to exercise in hypertensive patients.

BACKGROUND: The insertion/deletion ACE polymorphism (ACE I/D) regulates different levels of circulating and tissue ACE activities, which may induce diverse adrenergic responses to physiological stimuli. The aim of this study was to evaluate the influence of the ACE I/D polymorphism on the adrenergic response to isotonic exercise in middle-aged hypertensive patients. MATERIAL/METHODS: Submaximal exercise (on a treadmill, using the Naughton protocol at 75% of maximal heart rate) was performed in 34 patients homozygous for the ACE I/D polymorphism (ACE II and ACE DD) with untreated essential hypertension (II = 19, DD = 15). Plasma venous adrenaline and noradrenaline were measured at rest and at submaximal exercise. RESULTS: Plasma ACE activity was significantly higher in the hypertensive patients carrying the ACE DD genotype compared with the ACE II group. Left atrium size, as well as LV dimensions, mass, and function, were similar in both groups. Total exercise time, baseline and 75% maximal heart rate (MHR) and blood pressure were similar in both groups. Baseline plasma adrenaline and noradrenaline levels were similar in both groups and increased significantly (p<0.05) by ca. 300% at submaximal exercise without differences between groups. CONCLUSIONS: The presence of the D allele on the ACE gene in middle-aged hypertensive patients determines higher circulating ACE activity but not increased sympathetic activity in response to submaximal exercise.

Adult↗